Concealed slide fastener

ABSTRACT

A slide fastener of the concealed or masked type having a pair of similar stringer tapes carrying along respective longitudinal edges a row of interlocking fastener elements. The stringer tape consists of a warp-knit structure having a web portion and a marginal edge portion interconnected by an interwale groove which defines an axis of fold along which the tape is folded on itself and which is greater in width than the rest of interwale grooves.

United States Patent 1191 Takamatsu 1 Aug. 26, 1975 1 CONCEALED SLIDE FASTENER {75] Inventor:

[73] Assignee: Yoshida Kogyo Kabushiki Kaisha,

Tokyo, Japan [23] Filed: Nov. 22, 1974 [21] Appl. No; 526,243

lkuo Takamatsu, Uozu, Japan [30] Foreign Application Priority Data Nov, 27, 1973 Japan 48-136937 [52] US. Cl. 24/205.1 C; 24/2()5.l6 C

[51] Int. Cl. .1 A44b 19/12; A44b 19/34 [58] Field of Search 24/205.1 C, 205.16 C

[56] References Cited FOREIGN PATENTS OR APPLICATIONS Germany 24/2(15.16 C

Primary lituminer-Bernard A. Gelak Almmey, Agent, or Firm-Bucknam and Archer 57] ABSTRACT A slide fastener of the concealed or masked type having a pair of similar stringer tapes carrying along respective longitudinal edges :1 row of interlocking fastener elements. The stringer tape consists of a Warpknit structure having a web portion and a marginal edge portion interconnected by an interwale groove which defines an axis of fold along which the tape is folded on itself and which is greater in width than the rest of interwale grooves.

1 Claim, 2 Drawing Figures CONCEALED SLIDE FASTENER BACKGROUND OF THE INVENTION This invention relates to slide fasteners, more particularly to a slider-operated fastener of the concealed or masked type which in its closed disposition substantially simulates a garment seam.

Slide fasteners having two rows of interlocking fastener elements formed from a continuous filament or wire and secured to respective folded edges of opposed stringer tapes are well known, and such fasteners when closed by the slider mask the elements from external view, only leaving a linear scam in the junction of the opposed tapes.

The so-called concealed" slide fasteners of known type are designed to maintain the effect of concealing or masking the fastener elements by folding the respective element-carrying edges of stringer tapes on themselves about the sewn seam which secures the respective row of fastener elements to the tape and which extends longitudinally of the tape and outermost of the elements or close to the coupling heads thereof. Such known concealed type slide fasteners include stringer tapes of a warp-knitted structure having on one surface alternate longitudinal wales and interwale grooves, with fastener elements mounted on the other flat surface along the respective longitudinal edges of the tapes which are folded, When attaching such a fastener to a garment or the like, it is necessary to unfold and erect the respective folded edges with the coupling heads of the fastener elements directed towards the plane of the garment and thereafter to sew the respective stringer tapes precisely along a particular longitudinal interwale groove closest to the coupling heads of the elements. However. when the respective elementcarrying edges of the tapes are thus erected substantially in an L-shaped fashion, the wales located on opposite sides of the interwale groove through which the sewing threads are to extend are urged towards each other, causing that particular interwale groove to be narrowed or otherwise crushed with the results that the sewing needle is liable misguided into other adjacent grooves away from the fastener elements. This has often led to mal-functioning of the concealed fastener.

SUMMARY OF THE INVENTION With the above-noted deficiencies of the prior-art slide fasteners in view, it is an object of the present invention to provide an improved concealed slide fastener comprising warp-knitted stringer tapes which will enable a sewing machine needle to pass through and along a desired location close to the coupling heads of the fastener elements thereby obtaining a proper line of sewn seam that secures the fastener to a garment or the like.

To achieve this object and other related objects hereinafter set forth, the present invention provides a concealed slide fastener comprising a pair of stringer tapes formed of a warp-knit structure and carrying rows of fastener elements along their respective longitudinal edges, each of said stringer tapes having on one surface a multiplicity of longitudinally extending alternate wales and interwale grooves. a particular one of said interwale grooves located immediately adjacent the coupling heads of the fastener elements being greater in width than the rest of interwale grooves and serving as a longitudinal axis of fold along which the stringer tape is folded on itself.

The features which are believed to be novel and characteristic of the invention are set forth with particularity in the appended claims, and will appear clear from the following description taken in conjunction with the accompanying drawings which illustrate by way of example a preferred embodiment and in which like reference characters denote like or corresponding parts throughout the views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a transverse sectional view of a concealed slide fastener stringer provided in accordance with the invention, the chain-dot line representing the unfolded position of the stringer tape; and

FIG. 2 is a transverse sectional view of the fastener stringer with its element-carrying edge held erect for sewing the fastener to a garment fabric.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and particularly to FIG. 1, there is shown a concealed type slide fastener 10 which essentially comprises a pair of similar stringer tapes 11 (but for purposes of illustration, one of such tapes is shown) and a row of interlocking fastener elements attached to the respective tape. More specifically, the row of elements 12 in the form of a spring coil is secured by means of sewing threads 13 to and along a longitudinal edge of the tape 11 and through the medium of a filler cord 14 inserted longitudinally through the space between opposed legs 12a, 12b of the elements 12 in the usual manner. The stringer tape 11 is provided with a web portion 11a having on one surface a multiplicity of alternate wales l5 and interwale grooves 16, while the other surface of said portion is rendered flat, on which the row of elements 12 is mounted. A tape of this structure is preferrably formed by warp knitting for example with use of longitudinally extending chain stitches which form the wales l5, tricot stitches and transversely extending lapping threads laid in coursewise to interconnect the chain stitches, with the grooves 16 formed longitudinally between adjacent wales 15.

In accordance with the features of the invention, the stringer tape 11 is provided with a longitudinal marginal edge portion 11b contiguous to the web portion 11a for mounting thereon a row of fastener elements 12, the two portions being interconnected by an interwale groove 16 which is greater in width than the rest of grooves 16.

The selected interwale groove 16' which lies immediately adjacent the coupling heads of the fastener elements 12 is utilized as a longitudinal axis of fold along which the tape 11 is folded on itself in the known manner to conceal or mask the row of fastener elements 12 when the fastener 10 is closed by a slider not shown. By reason of increased width of the selected interwale groove 16", the sewing needle 17 is allowed to pass precisely through and along the groove 16 without interference by adjacent wales 15 on opposite sides of the groove 16', so that there can be obtained a neatly arranged line of stitching 18 within the groove 16 which secures the fastener 10 to a garment fabric 19. Another advantage of this is that the tape 11 can be alternate wales and interwale grooves, a particular one of said interwale grooves located immediately adjacent the coupling heads of the fastener elements being greater in width than the rest of interwale grooves and serving a longitudinal axis of fold along which the stringer tape is folded on itself.

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1. A concealed slide fastener comprising a pair of stringer tapes formed of a warp-knit structure and carrying rows of fastener elements along their respective longitudinal edges, each of said stringer tapes having on one surface a multiplicity of longitudinally extending alternate wales and interwale grooves, a particular one of said interwale grooves located immediately adjacent the coupling heads of the fastener elements being greater in width than the rest of interwale grooves aNd serving as a longitudinal axis of fold along which the stringer tape is folded on itself. 